<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
</head>

<body>
  <script>
    class Father {
      constructor(uname) {
        this.uname = uname
        this.say = function () {
          console.log('1111');
        }
      }
      run() {
        console.log(22222);
      }
    }
    class Son extends Father {
      constructor(uname, sname) {
        super(uname)
        this.sname = sname
        this.ssay = function () {
          console.log('1111');
        }
      }
      srun() {
        console.log(22222);
      }
    }
    console.log(Son);
    var s = new Son('李四', '张三')
    console.log(s);
  </script>
</body>

</html>